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Earth could have as many as160 billion planetary neighbors in its home galaxy, according to astronomers.

In a new study,they conclude that each of the estimated 100 billion suns in the vast stellar spiral known as the Milky Way has at least one planet orbiting around it. And scientists say the huge number of these so-called "exo-planets" increases the likelihood that life might eventually be discovered on at least one of them.

Because they could not possibly count every planet in the Milky Way galaxy -- a pinwheel of stars more than 120 thousand light years across -- scientists analyzed selected data from observations of a small field of just 100 million distant stars, and then made an estimate of the number of planets in the entire galaxy.

The six-year project involved observations by 42 astronomers from around the world. A smaller group of scientists sifted through the data for evidence of microlensing, a kind of cosmic magnifying glass in which the light of a background star is bent, and brightened, by the gravitational field of another star passing directly in front of it.

When that foreground star is also circled by one or more planets with their own gravitational fields, the brightness of the microlensing shows a tell-tale fluctuation.

That can last hours or days, depending upon the size of the exoplanet and the duration of its orbit, according to Kailash Sahu of the Johns Hopkins University Space Telescope Institute in Maryland. Sahu helped develop the gravitational microlensing technique in the mid-1990s. The technique enables astronomers to detect very small and very distant planets, Sahu said.

“This is actually sensitive to finding planets far away from us, all the way to the outskirts of the galaxy. So we can get a real census of planets throughout the galaxy rather than a little box around the sun.”

Sahu said many of the stars astronomers analyzed have one or more planets. They found about 1500 of these alien solar systems within 50 light years of Earth.

According to scientists, two-thirds of all the exoplanets they detected with microlensing are probably about five times the size of Earth, and about one-fifth were the size of the gas giant Jupiter. But it is the Earth-sized planets that have captured the imagination of astronomers like Sahu.

“The Holy Grail will be to find planets, really Earth-like planets, with some things that can actually support life," said Sahu. "And so now we find that, yes indeed, Earth-like planets are common. So, the next thing would be to try to find which are the planets that can hold water and sustain life.”

So far, astronomers using a combination of ground-based and earth-orbiting space telescopes, including the U.S. space agency’s planet-hunting Kepler mission, have confirmed the existence of more than 700 planets outside our solar system. Another two-thousand candidate exoplanets are waiting to be verified.

The survey estimating as many as 160 billion planets in the Milky Way Galaxy is described in the January 12th issue of the journal Nature.

Manned deep space missions are still a long way off, but space agencies are already testing procedures, equipment and human stamina for operations in extreme environment conditions. Small groups of astronauts take turns in spending days in an underwater lab, off Florida’s southern coast, simulating future missions to some remote world. VOA’s George Putic reports.

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Manned deep space missions are still a long way off, but space agencies are already testing procedures, equipment and human stamina for operations in extreme environment conditions. Small groups of astronauts take turns in spending days in an underwater lab, off Florida’s southern coast, simulating future missions to some remote world. VOA’s George Putic reports.

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Fifty years ago, lawmakers approved, and U.S. President Lyndon Johnson signed, the Voting Rights Act of 1965. The measure outlawed racial discrimination in voting, giving millions of blacks in many parts of the southern United States federal enforcement of the right to vote. Correspondent Chris Simkins introduces us to some civil rights leaders who were on the front lines in the struggle for voting rights.

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Billions of dollars of so-called ‘dirty money’ from the proceeds of crime - especially from Russia - are being laundered through the London property market, according to anti-corruption activists. As Henry Ridgwell reports from the British capital, the government has pledged to crack down on the practice.

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Ottawa, Illinois, is the hometown of W.D. Boyce, who founded the Boy Scouts of America in 1910. In Ottawa, where Scouting remains an important part of the legacy of the community, the end of the organization's ban on openly gay adult leaders was seen as inevitable. VOA's Kane Farabaugh reports.

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Artificial limbs, including the most complex of them – the human hand – are getting more life-like and useful due to constant advances in tiny hydraulic, pneumatic and electric motors called actuators. But now, as VOA’s George Putic reports, scientists in Germany say the future of the prosthetic hand may lie not in motors but in wires that can ‘remember’ their shape.

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A British pro-democracy group has accused Russia of abusing the global law enforcement agency Interpol by requesting the arrest and extradition of political opponents. A new report by the group notes such requests can mean the accused are unable to travel and are often unable to open bank accounts. VOA's Henry Ridgwell reports.

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Talks on a major new trade agreement among 12 Pacific Rim nations are said to be nearing completion in Hawaii. Some trade experts say the "positive atmosphere" at the discussions could mean a deal is within reach, but there is still hard bargaining to be done over many issues and products, including U.S. drugs and Japanese rice. VOA's Jim Randle reports.

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Earth is in the midst of its sixth mass extinction. The last such event was caused by an asteroid 66 million years ago. It killed off the dinosaurs and practically everything else. So scientists are in a race against time to classify the estimated 11 million species alive today. So far only 2 million are described by science, and researchers are worried many will disappear before they even have a name. VOA’s Rosanne Skirble reports.

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Scientists have long been trying to develop an effective protection and cure for malaria - one of the deadliest diseases that affects people in tropical areas, especially children. As the World Health Organization announces plans to begin clinical trials of a promising new vaccine, scientists in South Africa report that they too are at an important threshold. George Putic reports, they are testing a compound that could be a single-dose cure for malaria.

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The latest issue of 'New York' magazine features 35 women who say they were drugged and raped by film and television celebrity Bill Cosby. The women are aged from 44 to 80 and come from different walks of life and races. The magazine interviewed each of them separately, but Zlatica Hoke reports their stories are similar.

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The United States is promising not to give up its fight against what Secretary of State John Kerry calls the “scourge” of modern slavery. Officials released the country’s annual human trafficking report Monday – a report that’s being met with some criticism. VOA’s National Security correspondent Jeff Seldin has more from the State Department.

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Abandoned more than 50 years ago, the underground streetcar station in Washington D.C.’s historic DuPont Circle district is about to be reborn. The plan calls for turning the spacious underground platforms - once meant to be a transportation hub, - into a unique space for art exhibitions, presentations, concerts and even a film set. Roman Mamonov has more from beneath the streets of the U.S. capital. Joy Wagner narrates his report.

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Greece has replaced Italy as the main gateway for migrants into Europe, with more than 100,000 arrivals in the first six months of 2015. Many want to move further into Europe and escape Greece’s economic crisis, but they face widespread dangers on the journey overland through the Balkans. VOA's Henry Ridgwell reports.

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After the closure of a major rubbish dump a week ago, the streets of Beirut are filling up with trash. Having failed to draw up a plan B, politicians are struggling to deal with the problem. John Owens has more for VOA from Beirut.

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A U.N. climate conference in December aims to produce an ambitious agreement to fight heat-trapping greenhouse gases. But many local governments are not waiting, and have drafted their own climate action plans. That’s the case with Paris — which is getting special attention, since it’s hosting the climate summit. Lisa Bryant takes a look for VOA at the transformation of the French capital into an eco-city.